The M4 Harris is an Everetti third generation and fourth generation main battle tank (MBT), produced in the Union of Everett. It is named after the first Secretary of Defense of the Union of Everett, Jason M. Harris. Highly mobile, designed for modern armored ground warfare, the M4 is well armed and heavily armored. Notable features include the use of a hydrogen fuel-cell turbine engine, the use of sophisticated composite armor, and separate ammunition storage in a blow-out compartment for crew safety.